Microstructure and mechanical properties of (FeCoNi)(100-x)(NiAl)(x) eutectic multi-principal element alloys

摘要

Eutectic multi-principal element alloys exhibit homogeneously fine microstructure, excellent castability and good industrial application prospect. In this work, the microstructure and mechanical properties of (FeCoNi)(100-x)(NiAl)(x) eutectic multi-principal element alloys are studied. The phase constitution of the studied FeCoNiAl systems is FCC+B2 NiAl-type phases. With Al concentration increasing from 11 to 28 at%, the phase constitution changes from divorced-eutectic structure with FCC being the primary phase to divorced-eutectic structure with B2 being the primary phase. The compressive yield strength of FeCoNiAl increases continuously from 201 to 899 MPa with Al content increasing from 11 to 28 at%. The improved strength can be correlated with the increased volume fraction of NiAl-type phase. Moreover, the experimental results are compared with the prediction by the Calphad method using the TTNI8 database. Finally, the stability of eutectic phases in MPEAs is discussed. (C) 2021 Elsevier B.V. All rights reserved.